In a manufacturing process of a semiconductor device, an impurity introduction process for introducing impurities into a substrate is executed for forming, for example, an n-type semiconductor and a p-type semiconductor. After the introduction of impurities, an annealing process (thermal treatment) is executed.
For example, when using a silicon wafer as a substrate, an ion implantation process for implanting ions into the wafer by allowing impurity ions to collide with the wafer and the annealing process for coupling the implanted impurities with silicon are executed.
It is necessary to suppress the diffusion of impurities into a deep part in the substrate for miniaturizing the semiconductor device and for improving the performance thereof. For that purpose, it is required that the impurities are introduced to a shallow region near the surface of the substrate with high density as well as the annealing process for coupling the impurities with silicon be performed for a short period of time. When the thermal treatment is performed for a long period of time, the impurities are diffused to the deep part of the substrate. As a result, it is difficult to fabricate a good semiconductor device. Accordingly, a technique of performing annealing process for a short period of time is required.
As a technique of performing annealing process for a short period of time, for example, a heating technique using laser is used. In the case of heating using the laser, a heating target can be heated to 1000° C. or more for a short period of time as the order of μs.
However, as there is a limit in continuous output time of laser at present, it is necessary to emit the laser plural times when the surface of a large-sized substrate is scanned with the laser to heat the substrate. Accordingly, there is a case where the degree of heating differs in plural portions of the substrate which has been scanned with laser emitted at different timings. That is, heating unevenness of substrate may occur. As a result, semiconductor devices to which the annealing process has been sufficiently performed and semiconductor devices to which the annealing process has been insufficiently performed are fabricated.
A semiconductor manufacturing apparatus capable of solving the problem of the annealing process by the laser is disclosed in JP-A-2013-120684 (Patent Document 1). The semiconductor manufacturing apparatus described in Patent Document 1 is configured to move a substrate relatively to a plasma torch unit so that the substrate crosses the front of an opening of the plasma torch unit for emitting plasma. The opening for emitting plasma has a slot shape elongated in a direction orthogonal to the moving direction of the substrate, which is longer than a width (size in the direction orthogonal to the moving direction) of the substrate. The plasma is emitted from the opening in a line shape onto the surface of the substrate on which semiconductor devices are formed. Therefore, the surface of the substrate is scanned once with the line-shaped plasma, thereby heating the entire substrate uniformly without occurrence of heating unevenness. As a result, the annealing process is performed uniformly with respect to plural semiconductor devices on the substrate.